4-4" ports

making a box sunday for a buddy. he has a lot of 4" pvc. do you guys think 4 4" ports would be enough for very old kicker comp 15's? i think the box is 11 cubes with the ports 11" long for 32hz tuning.

Re: 4-4" ports

thats what i thought. he said the kicker manual has a 3.5 cube box with one 4" port for the subs that he has. that was for one 15". so he was going to use 3 i said to use at least 4 but it still seemed to small. i also have 8" sonotube around. would 2 of the sonotubes work?